Health troubles persist for 9/11 rescue workers

It was late in the night when James Zadroga, sleeping beside his 4-year-old daughter, woke up to fetch her some milk. It was no easy errand: The former New York City police detective's lungs were so scarred that he needed supplemental oxygen to breathe.

In 2001, after the attack on the World Trade Center, he had donned a paper mask and toiled at Ground Zero on rescue and recovery missions. Then he developed a cough and damaged lungs. Four years later, the 34-year-old was dying.